204 research outputs found

    Phase diagrams of correlated electrons: systematic corrections to the mean field theory

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    Perturbative corrections to the mean field theory for particle-hole instabilities of interacting electron systems are computed within a scheme which is equivalent to the recently developed variational approach to the Kohn-Luttinger superconductivity. This enables an unbiased comparison of particle-particle and particle-hole instabilities within the same approximation scheme. A spin-rotation invariant formulation for the particle-hole instabilities in the triplet channel is developed. The method is applied to the phase diagram of the t-t' Hubbard model on the square lattice. At the Van Hove density, antiferromagnetic and d-wave Pomeranchuk phases are found to be stable close to half filling. However, the latter phase is confined to an extremely narrow interval of densities and away from the singular filling, d-wave superconducting instability dominates

    The effect of soil conditioner on the spatial variability of soil environment

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    ArticleThe aim of the study was to assess and evaluate the effect of soil conditioner on the spatial variability of soil environment. Activator PRP-SOL conditioning soil properties was selected as a field of study. Assessment of soil environment was done through the evaluation of selected soil properties, namely, tensile resistance of the soil and soil infiltration ability. Two dose of PRP-SOL application was done twice in year 2015 (Autumn and Spring) and once in 2016 (Spring) with application rates 150 kg ha-1 and 140 kg ha-1 , respectively. The area was divided into blocks where stimulators were applied and none treated as a control. The evaluation of recorded values showed that treatability and tillage itself was significantly better on the area which was treated by application of PRP-SOL activators. In addition, tensile resistance was decreased by 5.71% in comparison with non-treated area of experimental field. Since the infiltration ability is among the very important soil properties which have an effect on soil moisture regime as well as surface runoff and therefore soil erosion. The evaluation of recorded values has revealed the effect of treatment by PRP-SOL activators on soil infiltration ability and therefore it results in increases infiltration of precipitation as well. Overall increase of infiltration was recorded at value 2 mm h -1 . It can be concluded that application of soil activators may increase the soil conditions and therefore not only conserve soil fertility but even increase it from the long term perspective

    Chiral d+is superconducting state in the two dimensional t-t' Hubbard model

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    Applying the recently developed variational approach to Kohn-Luttinger superconductivity to the t-t' Hubbard model in two dimensions, we have found, for sizeable next-nearest neighbor hopping, an electron density controlled quantum phase transition between a d-wave superconducting state close to half filling and an s-wave superconductor at lower electron density. The transition occurs via an intermediate time reversal breaking d+is superconducting phase, which is characterized by nonvanishing chirality and density-current correlation. Our results suggest the possibility of a bulk time reversal symmetry breaking state in overdoped cuprates

    Validation of a Method to Prepare Artificial Chylomicron Remnant-like Particles

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    1 página. Proceedings and Abstracts of the 2nd International Symposium on Chylomicrons in Disease-2 (ISCD2)Resumen póster.Peer reviewe

    Effect of particle size on functional and mechanical properties of single crystals of iron-based FeNiCoAlNb alloy

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    It is shown that [001]-single crystals Fe-28%Ni-17%Co-11.5%Al-2.5Nb (at. %) alloy aged at T=973 K, 1−20 hours are observed γ'-phase particle size of 3-25 nm, which give rise to thermoelastic of the γ-α′ martensitic transformation. The effect of size of γ'-phase particle on the critical stress of high temperature phase, the temperature range of superelasticity and the mechanical hysteresis are investigated

    Bond formation at polycarbonate | X interfaces (X = Al2_2O3_3, TiO2_2, TiAlO2_2) studied by theory and experiments

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    Interfacial bond formation during sputter deposition of metal oxide thin films onto polycarbonate (PC) is investigated by ab initio molecular dynamics simulations and X-ray photoelectron spectroscopy (XPS) analysis of PC | X interfaces (X = Al2_2O3_3, TiO2_2, TiAlO2_2). Generally, the predicted bond formation is consistent with the experimental data. For all three interfaces, the majority of bonds identified by XPS are (C-O)-metal bonds, whereas C-metal bonds are the minority. Compared to the PC | Al2_2O3_3 interface, the PC | TiO2_2 and PC | TiAlO2_2 interfaces exhibit a reduction in the measured interfacial bond density by ~ 75 and ~ 65%, respectively. Multiplying the predicted bond strength with the corresponding experimentally determined interfacial bond density shows that Al2_2O3_3 exhibits the strongest interface with PC, while TiO2_2 and TiAlO2_2 exhibit ~ 70 and ~ 60% weaker interfaces, respectively. This can be understood by considering the complex interplay between the metal oxide composition, the bond strength as well as the population of bonds that are formed across the interface
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